Low Idle, Lower Voltage

[beakie]

My 97 has started running with a slightly less voltage than normal, normal sits right on 14, now its probably around 12-13.
With that my idle when warm is about 650-700RPM.
Yesterday and for the last few days it has been starting odd. I usually turn the key, starts right up and thats that. Lately I need to turn the key for a little longer, and yesterday I had to try twice, not that it wouldn't start the first time, I let it go as I thought it had caught, but it didn't. Than I stopped for gas and when I tried to start it I heard a single 'click' tried and 'click' thats it a few times. Popped the hood, disconnected everything but the needed cables (I have butterfly nuts on my marine post connecters) and it started right up. Could be the post were just loose, but then I noticed my voltage lower than normal, and when I stopped the RPM's being that low.
I also notice more engine noise in the last 3 weeks than in the past, not knocking, but just louder noise. Hard to explain.
Now I did have the Jeep in water upto the door (5" of lift n 33's) so the alt probably got wet even tho I was really just wadding not flying thru it. And I drove the rig at about 150kph for about 20 minutes a month ago on a super long straight away near where I live, stupid yes I know and regrettable.

So all I can think of, is getting the battery/alt tested (not quite 2 years old) and replacing if needed, at which time I'll step upto a Durango alt.

Any ideas on why my idle and rpm's are so low?
thanks for your help, searching didn't answer exactly as many were on Renix systems.

 

[jeepsrock]

Its very possible that your low idle is just a coincidence due to the water hitting a sensor of some kind..possibly the tps. Also the fact your having a low voltage could also signal that the starter is going south and is causing your starter to draw to much current and read as a low voltage. After you get her going and drive her for a while does the voltage go back up ?

PEte

 

[Ecomike]

The low voltage probably is causing the low idle.

Sounds like the alternator is dying, or died. They do not like water, no matter what brand alternator you buy. If you are going to drag them through water or mud hit the JY and get some cheap spares!

The battery could also be dying and not supplying enough voltage to the alternator and the starter. But the running it through water says test the alternator first, then the battery next. Could be both. I once had a bad battery that damaged the alternaotr and starter and had to replace all three within a week of each other, so dont wait tell it dies to figure it out and fix it!

The battery should have a good 12.9 volts on it when fully charged. With the engine running it should hold about 14 volts. If it is running at less than 13 volts then the alternator (and) or battery is dying.

 

[beakie]

ok, been away from net for a bit.
I took the battery in and it was bad, test took seconds to say 'replace'
problem still occurs. idle is still below 700rpm, voltage is a little better, closer to 14v when running, whether just started or 2 hour drive.
I unbolt the bettery anytime its gonna sit for anymore than 20 minutes, as it still drains down to empty if left off. I've been away from home (shops, tools and such) and will be till Tuesday or so, until then I just drive (runs fine other than idle) and unbolt battery when not running. Not that bad as I have marine terminals with butterfly nuts so the are quick, but can be annoying at mall or gym or anytime I want to stop somewhere for an unknown period of time.
When I get back home I will try and track down any shorts, aswell as get a new alt and starter, last time I replaced them with JY's so I'll spend the extra money and get good ones. I don't plan on being in water again, and also will be looking into raising the alt upto the A/C's mount. thanks for the help, and confirmation on what I think may be wrong, here's hoping we're right and this is an easy swap n fix.

 

[scottmcneal]

alt, did you have it tested? My alt would kill my battery in about three hours

 

[beakie]

I haven't had the alt tested, its charging fine, and I have driven it like this for the last 2 weeks (granted only 5 hours total)
The Alt seems fine, unless its the diode I have read about, that will drain the battery slowly overnight.
When I turn it on, it jugs as if its gonna konk out, sounds dea, than chugs back to life... idles low but drives fine. the Tach flutters from 650-700rpm when stopped, but the volts sit at 13 steady.
I am off next week, gonne make some changes under hood, clean up all my wiring, remove A/C comp move 136amp alt up top, and remove clutch fan for elec. Will have to give a good look for any shorts, and if nothing is found and problems still here, will take it to buddy mech who will check it out for me.